In X-ray tomosynthesis, a series of low dose X-ray images are acquired over a range of X-ray beam orientations relative to an imaged object. Digital tomosynthesis (DTS) is a limited angle imaging technique, which allows the reconstruction of tomographic planes on the basis of the information contained within the images acquired during one tomographic image acquisition. More specifically, DTS is reconstruction of three-dimensional (3D) images from two-dimensional (2D) projection images of an object.
In DTS, one back-projection technique known as “simple back-projection” or the “shift and add algorithm” is often used to reconstruct 2D images into 3D images. This technique requires a relatively straightforward implementation and minimal computational power requirements.
A reconstruction method used in tomosynthesis is known as the algebraic reconstruction technique (ART). Another reconstruction technique used in computed tomography (CT) imaging (i.e., filtered back-projection) utilizes projections over the full angular range (i.e., full 360.degree. image acquisition about the object to be imaged) and a fine angular spacing between projections. Within this framework, filtered back-projection is a reconstruction method that yields high quality reconstructions with few artifacts.